10g

11g

The initialization parameter should be set to DIAGNOSTIC+TUNING (default) or DIAGNOSTIC to enable automatic database diagnostic monitoring. Setting CONTROL_MANAGEMENT_PACK_ACCESS to NONE disables many Oracle Database features, including ADDM, and is strongly discouraged, but seems to be the only way to disable the automatic monitoring.

Tuning relies on having a diagnostic license which explains why the options are NONE, DIAGNOSTIC or DIAGNOSTIC+TUNING